/*
	This file is part of the OdinMS Maple Story Server
    Copyright (C) 2008 Patrick Huy <patrick.huy@frz.cc> 
                       Matthias Butz <matze@odinms.de>
                       Jan Christian Meyer <vimes@odinms.de>

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU Affero General Public License version 3
    as published by the Free Software Foundation. You may not use, modify
    or distribute this program under any other version of the
    GNU Affero General Public License.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU Affero General Public License for more details.

    You should have received a copy of the GNU Affero General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

package net.sf.odinms.tools;

/**
 * Provides a class with tools for working with IP addresses, in both strings
 * and as long integers.
 * 
 * @author Nol888
 * @version 0.1
 * @since Revision 890
 */
public class IPAddressTool {
	/**
	 * Dummy constructor for static classes.
	 */
	private IPAddressTool() {
	}

	/**
	 * Converts a dotted-quad IP (<code>127.0.0.1</code>) and turns it into
	 * a long integer IP.
	 * 
	 * @param dottedQuad The IP address in dotted-quad form.
	 * @return The IP as a long integer.
	 * @throws RuntimeException
	 */
	public static long dottedQuadToLong(String dottedQuad) throws RuntimeException {
		String[] quads = dottedQuad.split("\\.");
		if (quads.length != 4) {
			throw new RuntimeException("Invalid IP Address format.");
		}

		long ipAddress = 0;

		for (int i = 0; i < 4; i++) {
			int quad = Integer.parseInt(quads[i]);
			ipAddress += (long) (quad % 256) * (long) Math.pow(256, (double) (4 - i));
		}

		return ipAddress;
	}

	/**
	 * Converts a long integer IP into a dotted-quad IP.
	 * 
	 * @param longIP The IP as a long integer.
	 * @return The IP as a dotted-quad string.
	 * @throws RuntimeException
	 */
	public static String longToDottedQuad(long longIP) throws RuntimeException {
		StringBuilder ipAddress = new StringBuilder();

		for (int i = 0; i < 4; i++) {
			int quad = (int) (longIP / (long) Math.pow(256, (double) (4 - i)));
			longIP -= (long) quad * (long) Math.pow(256, (double) (4 - i));
			if (i > 0) {
				ipAddress.append(".");
			}
			if (quad > 255) {
				throw new RuntimeException("Invalid long IP address.");
			}
			ipAddress.append(quad);
		}

		return ipAddress.toString();
	}
}
